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When to plant Yarrow in Chaffee County County,

Chaffee County County sits in cold Zone 5b. Plant Yarrow June 16–July 7 for the single annual harvest; the September 7 first frost closes the window.

When to Plant Yarrow in Chaffee County, CO

Chaffee County, Colorado Zone 5b June

June in Chaffee County, Colorado — your action list

Each item below is timed to Chaffee County, Colorado's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost June 16
Avg. first frost September 7
Soil temp (4") 47°F
Watering High
Pest pressure High
Daylight 14.7 hrs
  1. Plant out yarrow

    Your last frost (June 16) has passed. These warm-season crops can handle outdoor soil now.

  2. Scatter yarrow into prepared beds

    These tolerate cool soil, so you're not gambling by sowing now.

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Achillea millefolium (Yarrow) is a tough, drought-tolerant native perennial with aromatic finely-divided foliage and broad flat-topped flower clusters that serve as a landing platform for hundreds of beneficial insect species. Available in white (the species type) and a wide range of cultivars spanning yellow, gold, pink, salmon, and deep red. Spreads by rhizome to form ground-covering colonies; blooms from late spring through midsummer with reblooming into fall if deadheaded. Exceptional in hot, dry sites where other perennials fail.

Chaffee County, Colorado is in USDA Zone 5b. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 7,788 feet, Chaffee County receives approximately 18.6 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Yarrow during the growing season. With low rainfall, drip irrigation is essential for growing Yarrow successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Chaffee County, CO (Zone 5b) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Chaffee County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Yarrow Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 8 Transplant: Jun 24 🌸 Bloom: Sep 2 – Dec 16
Recommended (50%) ✗ May not fit
Start indoors: Apr 14 Transplant: Jun 30 🌸 Bloom: Sep 8 – Dec 22
Safe Start (90%) ✓ Fits season (269 days to spare)
Start indoors: Apr 24 Transplant: Jul 10 🌸 Bloom: Sep 18 – Jan 1

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Chaffee County

How your county's soil matches Yarrow's growing requirements.

Soil pH

Your soil pH (6.7–7.6) is more alkaline than Yarrow prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Chaffee County is excellent for Yarrow — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Yarrow.

How to Plant Yarrow

18"
Between Plants
24"
Between Rows

Yarrow Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Yarrow

Yarrow needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Yarrow Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 2.4" 0" ❄️ Dormant
Jun 2.2" 1.4" 0.8" 💧 Light watering
Jul 2.2" 1.8" 0.4" 💧 Light watering
Aug 2.2" 1.9" 0.3" 💧 Light watering
Sep 2.2" 1.4" 0.8" 💧 Light watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Chaffee County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Yarrow Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Yarrow needs ~1,088 GDD — county provides 1,203 GDD Good fit

Yarrow Planting Timeline — Chaffee County, CO

Yarrow Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors June 30 Jun 30 – Jul 14
Direct Sow June 16 Jun 16 – Jul 7
Bloom September 8 Sep 8 – Dec 22

· 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May
June Transplant Outdoors Direct Sow
July Transplant Outdoors Direct Sow
August
September Bloom
October Bloom
November Bloom
December Bloom

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

83 days in Chaffee County

Growing Tips for Yarrow in Chaffee County

Direct sow Yarrow outdoors after June 16 in Chaffee County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Chaffee County is tight for Yarrow (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Yarrow in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Chaffee County receives only 19" of rain annually. Yarrow needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 8–10 weeks before last frost; seeds need light for germination — press onto soil surface, do not cover. Direct sow after last frost or divide established clumps in spring or fall. Thrives in poor, well-drained soil — rich soil and high fertility cause floppy stems and reduce flower count. Avoid overwatering; excellent drought tolerance once established. Deadhead spent clusters to encourage rebloom. Divide every 2–3 years to prevent center die-out and control spread. Year 2+ plants bloom most heavily; first-year plants may produce limited flowers. Dried flowers retain color well for arrangements.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Yarrow in Chaffee County, CO?

Chaffee County is in Zone 5b with an average last frost of June 16. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.

What planting zone is Chaffee County, CO?

Chaffee County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 16 and first fall frost is September 7.

When should I plant Yarrow in Chaffee County, ?

In Chaffee County, , plant Yarrow after the last frost (around June 16) and before the first frost (around September 7). Best results when soil holds above 50°F.

What growing zone is Chaffee County, for Yarrow?

Chaffee County sits in USDA Zone 5b. Yarrow grows reliably in zones 3a through 9b, so it's a good fit here.

Can Yarrow grow in Chaffee County's climate?

Yes — Yarrow grows well in Chaffee County's temperate climate. Chaffee County averages a 83-day frost-free season, with last frost around June 16 and first frost around September 7.

🌱

Your Chaffee County Garden Planner — Free

A 22-page printable planner built for Chaffee County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Chaffee County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.